This invention relates to waterbeds, and more particularly to tubes for waterbeds.
The advantages and benefits of waterbeds over conventional beds are well-known. There have, however, heretofore been some perceived disadvantages of waterbeds which have slowed their acceptance. One of these perceived disadvantages has been the presence of a hard wooden frame around the outside of the waterbed mattress(es) to hold the mattress(es) in place.
This particular perceived disadvantage has been overcome in part recently by the introduction of softside waterbeds. These waterbeds use a layer of foam which extends as a collar around the periphery of the waterbed to hold the waterbed mattress in place. In soft-side waterbeds, the mattress is often composed of a plurality of parallel watercontaining tubes, which extend from head to foot of the mattress. When disposed in this manner, waterbed tubes substantially prevent side to side wave motion in the waterbed.
However, waterbed tubes could be improved. When a user lies on his side on a waterbed tube mattress, his shoulder may rapidly displace the water under the shoulder and force it to rush to the foot of the bed. The user's feet are then elevated in an exaggerated manner. As the water rebounds from the end of the tube, it shoots back toward the head of the bed, creating a "teeter-totter" effect.
Various systems, such as the foam or fiber-filled tubes disclosed in U.S. Pat. No. 4,221,013, address this problem, but they could be improved. For example, a foam-filled tube reduces the rapid water movement but does not eliminate the rapid displacement effect or the "teeter-totter" effect. Moreover, in foam-filled tubes the foam can bunch together in the filling, draining, moving or burping process, which significantly reduces the anti-wave properties. Foam is also a natural harbor for bacteria and air cells. The bacteria deteriorate the quality of the vinyl of which the tubes are made and diminish the life of the tube. Air trapped in the foam is released from the open cells and can cause annoying noises unless burped.
Upon draining a foam-filled tube, a substantial amount of water remains in the foam, creating an unnecessarily heavy tube which can be difficult to transport and which is also subject to bacterial, fungal and/or algae growth. Moreover, a foam-filled waterbed tube has a higher cubic volume than a non-foam filled tube, with the result that shipping costs are increased. This is particularly a problem in export containers.
Various foam-filled waterbed tubes have been devised to hold the foam or fiber in place in the tube. Unfortunately, these usually involve additional seals to the vinyl of the waterbed tube which can be uncomfortable to the user, and can, if they fail, result in a leak from the tube.